Introduction

In 1832 John Nicholson, then harbourmaster of Port Jackson (now better known
as Sydney Harbour), published the 'Code of Signals for the Colony of New South
Wales". The Nicholson Flag Chart consists of Marryat's Signals, with 16 flags
each for the Royal Navy and the Merchant Service, plus the Colonial Signals,
with 18 Descriptive Flags, 12 'Colonial Numerals for Pilots Reports &c.', and 12
'Proposed Miscellaneous Flags for N.S.Wales and the South Seas' (mostly
ensigns). Also included on the chart are five examples on how the signals would
be displayed to convey messages: the Descriptive Flags would be flown either on
their own, or with the Numeral Flags underneath which indicated the origins of
individual ships according to a pre-determined code list.

The Colonial
Signals were in use until circa 1940. By then the Descriptive Flags had four
more flags added; the Colonial Numerals became the Garden Island Weather Signals
to indicate wind speeds, with the Numeral Flags indicating a corresponding
Beaufort Scale.

The old Colonial Signals have been partially revived
since 2008, when a flagstaff was re-erected on Observatory Hill in Sydney, on
which signals flags had been flown from circa 1810 until the late 1930s. Among
the other flags flown on the flagstaff nowadays are some of the Descriptive
Flags, as well as the Colonial Numerals flown to indicate the day's maximum
temperature in Celsius. (See also
http://www.sydneyobservatory.com.au/whatson/flagstaff/) Miles Li,
7 September 2015

0 - Calm - less than
1 mph

image
by Miles Li, 22 July 2015

I'm not sure a flag signal to indicate there was no wind would be
very effective. But I understand the flags are just a numeric code, with the 0
being used for "10" as well.Peter Hans van den Muijzenberg, 17
August 2015

This is a modern (since 2008) flag, with a darker shade of red than the
original signal flags, to be flown above the Numeral Flags to indicate the day's
maximum temperature in Celsius.Miles Li, 7 September 2015

The Nicholson Flag Chart of 1832 illustrated a dozen "Proposed Miscellaneous
Flags" in four rows. Of particular interest is the third row, featuring the
purported flags for three island groups in the Pacific, which are illustrated
below.